Prognostic Value of Tissue Oxygen Monitoring and Regional Cerebral Oxygen Saturation Monitoring and Their Correlation in Neurological Patients with Sepsis: A Preliminary, Prospective, Observational Study.

Abstract

There is paucity of literature on the prognostic value of tissue oxygen saturation (StO2) and regional cerebral oxygen saturation (rSO2) in neurological patients with sepsis. In this preliminary study, we investigated the prognostic value of StO2 and rSO2 in a group of neurological patients and correlated StO2 and rSO2 with hemodynamic and metabolic parameters. This preliminary, prospective observational study was conducted in 45 adult neurological patients admitted to intensive care unit. Once a diagnosis of sepsis or septic shock was established, parameters of oxygenation (StO2, rSO2, central venous oxygen saturation [ScvO2]), serum lactate, illness severity scores (Acute Physiology and Chronic Health Evaluation score, Sequential Organ Failure Assessment score, Glasgow Coma Scale) were recorded at 0, 6, 12, 24, 36, and 48 hours, and once daily thereafter. Outcomes were in-hospital mortality attributable to sepsis and the Glasgow outcome score at hospital discharge. There was a moderately positive correlation between StO2 and rSO2 at baseline (r=0.599; P=0.001). StO2, illness severity scores and serum lactate, but not rSO2, were significantly different between survivors (n=29) and nonsurvivors (n=16) at baseline and during the first 48 hours. An rSO2 of 62.5% had a sensitivity of 83% and specificity of 67% to differentiate survivors and nonsurvivors of septic shock at 48 hours. StO2 had a higher correlation with ScvO2 and serum lactate than rSO2. StO2 prognosticates survival and favorable/unfavorable outcomes in neurological patients with sepsis. The role of rSO2 in predicting survival in milder form of sepsis is doubtful.